Some useful terms
APNOEAIC EPISODE (ap-knee-ic) A period of not breathing whilst asleep usually lasting for more than 10 seconds.
HYPERCAPNIA (high-per-cap-nee-ah) A raised level of carbon dioxide in the blood. This is the gas normally breathed out. Its blood level rises if breathing is inadequate. Usually measured by taking an arterial blood sample.
HYPERSOMNOLENCE (high-per-som-no-lence) Technical expression for excessive daytime sleepiness.
HYPNOGRAM (hip-no-gram) The final print out of the all-night sleep stages after an overnight study. (REM and non-REM).
HYPOPNOEA (high-pop-nee-ah) A period of underbreathing: usually for more than 10 seconds.
HYPOTHYROIDISM (high-po-thy-royd-ism) Also known as myxoedema (mix-ee-dee-ma). When the thyroid gland fails to make enough thyroid hormone. Can present as obstructive sleep apnoea.
HYPOXIA (high-pox-ee-ar) When the body is short of oxygen and therefore the level in the blood falls.
HYPOXIC DIPS (high-pox-ic) The falls in oxygen levels, seen on the oximeter, that usually accompany apnoeas. Also known as desaturations, because, when not hypoxic, the blood is described as fully saturated with oxygen.
INSOMNIA (in-som-nee-ah) Being awake when you want to be asleep. Often thought of as a problem but may not be. Common if people try to spend too long in bed.
MANOMETER (man-om-eater) Device to measure the pressure being delivered by a CPAP machine (usually measured in centimetres of water [cm H20] – where a common CPAP pressure is about 10).
MICRO AROUSALS Very brief “awakenings”, perhaps only seen when the brain waves (EEG) are being monitored.
MOVEMENT AROUSAL These are short awakenings with minor body movements, about which the sleeper is unaware.
MUFFLES™ Wax ear plugs. Less comfortable than the foam ones (EAR™) but more effective. From most chemists.
NARCOLEPSY (nar-co-lep-si) A cause of daytime sleepiness due to an inherited disorder of the control of dreaming sleep. Has to be differentiated from sleep apnoea, periodic leg movements and other rarer causes of daytime sleepiness.
NASAL CPAP (nasal see-pap) The process of delivering a continuously raised airway pressure mask worn on the nose, hence Continuous Positive (as opposed to negative) Airway Pressure.
OBSTRUCTIVE SLEEP APNOEA (ap-knee-ah) This syndrome is commonly referred to as OSA (obstructive sleep apnoea/apnea) or
OSAS (obstructive sleep apnoea/apnoea syndrome). Usually made up of 30 or more periods of not breathing when asleep. Each period lasting for more than 10 seconds.